RAD-1 is a Phase I/II open label management algorithm for highly antiretroviral experienced HIV-infected children and adolescents with rapidly progressive or advanced HIV disease for whom current antiretroviral therapy is failing. RAD-1 evaluates novel combinations of RTIs and PIs in reducing viral load, and evaluates the safety and PK of these combinations. Where novel agents cannot be chosen because of extensive antiretroviral experience, a change from current therapy with administration of formerly experienced therapy is required.